When an electronic device operates, the internal electronic components thereof would produce heat. Therefore, a heat-dissipating unit is required to help in increasing the heat-dissipation efficiency of the electronic device to avoid burnout or other damages of the electronic components due to overheating. The heat-dissipating unit is mainly a radiating fin assembly or a heat sink. Since the above-described heat-dissipating unit alone can only achieve limited effect in dissipating the heat produced by the electronic components, at least one cooling fan is associated with the heat-dissipating unit, so that the cooling fan produces and forces airflows through the heat-dissipating unit to achieve upgraded overall heat dissipation efficiency thereof. Conventionally, the cooling fan is associated with the heat-dissipating unit by directly fixing the cooling fan to the radiating fins of the heat-dissipating unit using fastening elements. By doing this, the radiating fins of the heat-dissipating unit are subject to deformation or even damage. The deformed or damaged radiating fins would result in narrowed flow passages and accordingly wind resistance to adversely affect the heat dissipation. Alternatively, the cooling fan is fixed to the heat-dissipating unit via a separate mounting rack in an attempt to solve the problem of deformed radiating fins and narrowed flow passages. To do so, additional screws or other types of fastening elements are needed to stably and firmly fix the cooling fan and the mounting rack to the heat-dissipating unit.
Please refer to FIG. 1 that is an exploded perspective view of a conventional thermal module 1. As shown, the thermal module 1 includes a cooling fan 11, a mounting rack 12, and a heat sink 13. The cooling fan 11 is provided at four corners with a through hole 111 each. A plurality of screws 14 is threaded through the through holes 111 to lock the cooling fan 11 to the mounting rack 12. The mounting rack 12 is provided at two opposite lower lateral sides with a retaining arm 121 each. The retaining arms 121 can be engaged with notches 131 formed on two lateral sides of the heat sink 13, so as to fixedly hold the cooling fan 11 to the heat sink 13. While the thermal module 1 has the cooling fan 11 connected to the heat sink 13 via the mounting rack 12, a lot of labor and time is needed to do such assembly and thereby increases the manufacturing cost of the thermal module 1. Moreover, the cooling fan 11 vibrates when it operates, bringing the whole thermal module 1 to produce noise or vibration. In brief, the conventional thermal module with a cooling fan has the following disadvantages: (1) having complicated structure; (2) requiring a lot of time and labor to assemble; (3) having increased manufacturing cost; and (4) easy to produce vibration.
It is therefore tried by the inventor to develop an improved cooling fan housing assembly and a thermal module with such cooling fan housing assembly to overcome the drawbacks existed in the prior art cooling fan housing assemblies and thermal modules.